Model 7002Switch System Instruction Manual - Advanced Test ...

IEEE-488 ReferenceProgramming Example ⎯ Use the following statement toperform a DCL:CLEAR 7When the RETURN key is pressed, the instrument will performthe DCL.5.8.6 SDC (selective device clear)The SDC command is an addressed command that performsessentially the same function as the DCL command. However,since each device must be individually addressed, theSDC command provides a method to clear only selected instrumentsinstead of clearing all instruments simultaneously,as is the case with DCL.Programming Example ⎯ Use the following statement toperform an SDC:CLEAR 707This sends the following IEEE-488 commands: UNT UNLLISTEN 07 SDC. When the statement is executed, the instrumentperforms the SDC.5.8.7 GET (group execute trigger)GET is a GPIB trigger that is used as an arm, scan and/orchannel event to control the scanning process. The Model7002 will react to this trigger if it is the programmed controlsource. The control source is programmed from the SCPI:TRIGger Subsystem (see paragraph 5.18).With the instrument programmed and waiting for a GPIBtrigger, the following programming statement will providethe GET:TRIGGER 707This sends IEEE-488 commands UNT UNL LISTEN 07GET. When the ENTER key is pressed, the trigger event occurs.(The command TRIGGER 7 just sends GET. Any otherlisteners are triggered when the ENTER key is pressed.)5.8.8 SPE, SPD (serial polling)The serial polling sequence is used to obtain the Model 7002serial poll byte. The serial poll byte contains important informationabout internal functions, as described in paragraph5.6.8. Generally, the serial polling sequence is used by thecontroller to determine which of several instruments has requestedservice with the SRQ line. However, the serial pollingsequence may be performed at any time to obtain thestatus byte from the Model 7002.Programming Example ⎯ The SPOLL statement automaticallyperforms the serial poll sequence. To demonstrate serialpolling, enter in the following statements into thecomputer:S=SPOLL (707)PRINT “SPOLL BYTE =”;SAfter the first statement, the controller conducts the serialpolling sequence. After the second statement is executed, thedecimal value of the serial poll byte is displayed on the controllerCRT.5-31